glue for keel

[richard]

Have difficult to find the glue specified in plans.

Has anyone experience with waterproof polyurethane glue?

Richard

[richard]

Hi Ray,

I'm living in Europe....

[John Teetsel]

I don't know if Ace or HD has made it to Belgium yet. :wink:

Assuming you're going to use epoxy on the fiberglass, it's just as easy to use epoxy as a glue for the entire boat. The advantage to epoxy is that it works well on a less than perfect joint. Waterproof polyurethane glues like Titebond, Elmer's ProBond and Gorilla Glue need a pretty tight fit and lots of clamps to give maximum strength. Most are cheaper than epoxy, about $20 US for a gallon of Titebond II (you get a longer open time w/ Titebond II), vs about $55-$65 for the same amount of epoxy. Gorilla Glue is about the same cost as epoxy and gets mixed reviews on ease of use as it foams up a bit as it sets up and the squeeze out has to be cleaned up. I have no personal experience w/ Gorilla but like TBII very much for the right application.

Check here (and Google of course) for more info. http://www.rockler.com/ecom7/showoff.cfm?&DID=6&ObjectGroup_ID=217&CATID=63

Good luck.

[richard]

I know epoxy is probably the best, but I developped an allergy in the past and prefer to use something else where possible.

[Frank Hagan]

Richard, the "plastic resin glue" or "DAP Weldwood" glue is a Urea Formaldehyde glue, sold in a powder that is mixed with water.

The DAP website has a page on it at http://www.dap.com/retail/retail_detail.cfm?subcatid=103&catid=28&prodhdrid=42. Thier International directory doesn't list it, so the DAP brand may not be available there.

I know woodworkers in the UK use urea formaldehyde glue under different brand names. This site: http://www.randrtools.co.uk/it670007.htm has it in 3 liter tubs for about L20 (UK Pounds ... about 35 Euro?). That seems expensive to me, but you might search for it locally under the generic description of Urea Formaldehyde Glue. We buy it by weight instead of by the liter, and pay about $5 US a pound for it when buying it in the stores. I have no idea how many liters would be in a pound of the stuff ... its a light powder, about the consistency of white flour. Several Belgium plywood manufacturers use it, according to the quick Google search I made (I didn't try Google's European search engine, so I mainly got the UK references.) Greenpeace doesn't like it, so it may not be available everywhere.

I know that European boat builders use a very expensive waterproof glue, resorcinol, but I think this would be more expensive than using epoxy. But if you have an epoxy sensitivity, the extra cost is worth avoiding the suffering.

If the boat is to be in the water all of the time, then using a less expensive glue than resorcinol or epoxy probably isn't wise. But

if you are like most of us, and intend on keeping your boat on a trailer most of the time, then any waterproof glue certified for use outdoors would work. It may not be certified for "boat building", but as long as its certified for outdoor use you would be OK. Glues like Titebond Premium would work; its also pricey at about 25 pounds (40 euro?) per gallon in the UK at places like http://www.gluelines.co.uk/titebond.htm ... and it may be available locally cheaper. A gallon of this glue would probably do most of the boat. In the Stevenson Projects boats, you use both glue and screws in construction, so you don't have to use massive amounts of the adhesive to do the job.

[High C]

I've used Gorilla and the Titebond Polyurethane. I'm convinced they're the same thing. And PL Construction Adhesive in a caulk tube is also the same thing but thicker. All these are kind of hard to use. They set up fast, and foam as the excess oozes out. So you have to standby with a thinner soaked rag to wipe off what oozes. And you have to do it repeatedly, as the stuff keeps expanding. It's a lot like that expanding foam in a spray can that is used to insulate wall voids, or fill holes. It grows and grows! Kind of a pain, but it's supposed to make a strong bond if clamped tight, and is totally waterproof.

[Frank Hagan]

I know in finish work, the polyurethane glues leave a dark glue line, which isn't always wanted.

I think with the Weekender's construction technique, you could use the waterproof carpenter's glue ... Titebond Premium, I think ... that looks like the yellow carpenter's glue except its a tan color. Its designed for outdoor projects, and only slightly more expensive than the regular carpenter's glue.

[Andrew]

Richard

I've just put my keel together with a product called Purbond, its a polyurethane glue that goes on as a clear yellow gel and reacts with the moisture in the wood and then 'bubbles' and expands to fill in any gaps.

It worked really well, the only problem being that the keel must be clamped fairly hard or the expansion of the glue will force the keel apart. I did mine by laying it flat and putting half a dozen breeze blocks (cement bricks) on top of it - it cured in 10 hours at 4 degrees celcius (about 35F)

Andrew

[Mark Hughes]

I've been using the PL Polyurethane Construction Adhesive for the rubrails and cockpit construction, and so far I really like it. It dries a cream color, that is barely discernible between the rubrail and ply. It sands fairly well, and is strong as all get out. A bit troublesome to get off skin if you don't find it before it sets, but otherwise been great. Clamping pressure is definitely the key, although it will also expand to fill small voids.